Use the VList object to replace Parse.azVar for tracking the mapping between
SQL parameter names and parameter numbers. There is a performance
improvement, though there are still a few hiccups in the current code.
FossilOrigin-Name: 68ecafa1425a41358c88f41efea3262f1b4490f2
diff --git a/src/expr.c b/src/expr.c
index 60843bf..ae61074 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -934,7 +934,7 @@
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn". We make
-** sure "nnn" is not too be to avoid a denial of service attack when
+** sure "nnn" is not too big to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
@@ -981,30 +981,13 @@
** number as the prior appearance of the same name, or if the name
** has never appeared before, reuse the same variable number
*/
- ynVar i;
- for(i=x=0; i<pParse->nzVar; i++){
- if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
- x = (ynVar)i+1;
- break;
- }
+ x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
+ if( x==0 ){
+ x = (ynVar)(++pParse->nVar);
+ pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
}
- if( x==0 ) x = (ynVar)(++pParse->nVar);
}
pExpr->iColumn = x;
- if( x>pParse->nzVar ){
- char **a;
- a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
- if( a==0 ){
- assert( db->mallocFailed ); /* Error reported through mallocFailed */
- return;
- }
- pParse->azVar = a;
- memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
- pParse->nzVar = x;
- }
- if( pParse->azVar[x-1]==0 ){
- pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
- }
}
if( pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
sqlite3ErrorMsg(pParse, "too many SQL variables");
@@ -3430,9 +3413,11 @@
assert( pExpr->u.zToken[0]!=0 );
sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
if( pExpr->u.zToken[1]!=0 ){
- assert( pExpr->u.zToken[0]=='?'
- || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
- sqlite3VdbeAppendP4(v, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
+ const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
+ if( z ){
+ assert( pExpr->u.zToken[0]=='?' || strcmp(pExpr->u.zToken, z)==0 );
+ sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
+ }
}
return target;
}
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 0715609..d78d207 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1046,6 +1046,14 @@
typedef struct WhereInfo WhereInfo;
typedef struct With With;
+/* A VList object records a mapping between parameters/variables/wildcards
+** in the SQL statement (such as $abc, @pqr, or :xyz) and the integer
+** variable number associated with that parameter. See the format description
+** on the sqlite3VListAdd() routine for more information. A VList is really
+** just an array of integers.
+*/
+typedef int VList;
+
/*
** Defer sourcing vdbe.h and btree.h until after the "u8" and
** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
@@ -2952,7 +2960,6 @@
Token sLastToken; /* The last token parsed */
ynVar nVar; /* Number of '?' variables seen in the SQL so far */
- int nzVar; /* Number of available slots in azVar[] */
u8 iPkSortOrder; /* ASC or DESC for INTEGER PRIMARY KEY */
u8 explain; /* True if the EXPLAIN flag is found on the query */
#ifndef SQLITE_OMIT_VIRTUALTABLE
@@ -2964,7 +2971,7 @@
int iSelectId; /* ID of current select for EXPLAIN output */
int iNextSelectId; /* Next available select ID for EXPLAIN output */
#endif
- char **azVar; /* Pointers to names of parameters */
+ VList *pVList; /* Mapping between variable names and numbers */
Vdbe *pReprepare; /* VM being reprepared (sqlite3Reprepare()) */
const char *zTail; /* All SQL text past the last semicolon parsed */
Table *pNewTable; /* A table being constructed by CREATE TABLE */
@@ -3864,6 +3871,9 @@
defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
u64 sqlite3LogEstToInt(LogEst);
#endif
+VList *sqlite3VListAdd(sqlite3*,VList*,const char*,int,int);
+const char *sqlite3VListNumToName(VList*,int);
+int sqlite3VListNameToNum(VList*,const char*,int);
/*
** Routines to read and write variable-length integers. These used to
diff --git a/src/tokenize.c b/src/tokenize.c
index 0e60c56..c400dcd 100644
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -500,8 +500,7 @@
assert( pParse->pNewTable==0 );
assert( pParse->pNewTrigger==0 );
assert( pParse->nVar==0 );
- assert( pParse->nzVar==0 );
- assert( pParse->azVar==0 );
+ assert( pParse->pVList==0 );
while( 1 ){
assert( i>=0 );
if( zSql[i]!=0 ){
@@ -588,8 +587,7 @@
if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);
sqlite3DeleteTrigger(db, pParse->pNewTrigger);
- for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
- sqlite3DbFree(db, pParse->azVar);
+ sqlite3DbFree(db, pParse->pVList);
while( pParse->pAinc ){
AutoincInfo *p = pParse->pAinc;
pParse->pAinc = p->pNext;
diff --git a/src/util.c b/src/util.c
index a614f14..5ece922 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1453,3 +1453,92 @@
return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x);
}
#endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */
+
+/*
+** Add a new name/number pair to a VList. This might require that the
+** VList object be reallocated, so return the new VList. If an OOM
+** error occurs, the original VList freed, NULL is returned, and the
+** db->mallocFailed flag is set.
+**
+** A VList is really just an array of integers. To destroy a VList,
+** simply pass it to sqlite3DbFree().
+**
+** The first integer is the number of integers allocated for the whole
+** VList. The second integer is the number of integers actually used.
+** Each name/number pair is encoded by subsequent groups of 3 or more
+** integers.
+**
+** Each name/number pair starts with two integers which are the number
+** value for the pair and the size of the name/number pair, respectively.
+** The text name overlays one or more following integers. The text name
+** is always zero-terminated.
+**
+*/
+VList *sqlite3VListAdd(
+ sqlite3 *db, /* The database connection used for malloc() */
+ VList *pIn, /* The input VList. Might be NULL */
+ const char *zName, /* Name of symbol to add */
+ int nName, /* Bytes of text in zName */
+ int iVal /* Value to associate with zName */
+){
+ int nInt; /* number of sizeof(int) objects needed for zName */
+ char *z;
+ int i;
+
+ nInt = nName/4 + 3;
+ if( pIn==0 || pIn[1]+nInt > pIn[0] ){
+ /* Enlarge the allocation */
+ int nAlloc = (pIn ? pIn[0]*2 : 10) + nInt;
+ VList *pOut = sqlite3DbRealloc(db, pIn, nAlloc*sizeof(int));
+ if( pOut==0 ){
+ sqlite3DbFree(db, pIn);
+ return 0;
+ }
+ if( pIn==0 ) pOut[1] = 2;
+ pIn = pOut;
+ pIn[0] = nAlloc;
+ }
+ i = pIn[1];
+ pIn[i] = iVal;
+ pIn[i+1] = nInt;
+ z = (char*)&pIn[i+2];
+ pIn[1] = i+nInt;
+ assert( pIn[1]<=pIn[0] );
+ memcpy(z, zName, nName);
+ z[nName] = 0;
+ return pIn;
+}
+
+/*
+** Return a pointer to the name of a variable in the given VList that
+** has the value iVal. Or return a NULL if there is no such variable in
+** the list
+*/
+const char *sqlite3VListNumToName(VList *pIn, int iVal){
+ int i, mx;
+ if( pIn==0 ) return 0;
+ mx = pIn[1];
+ i = 2;
+ do{
+ if( pIn[i]==iVal ) return (char*)&pIn[i+2];
+ i += pIn[i+1];
+ }while( i<mx );
+ return 0;
+}
+
+/*
+** Return the number of the variable named zName, if it is in VList.
+** or return 0 if there is no such variable.
+*/
+int sqlite3VListNameToNum(VList *pIn, const char *zName, int nName){
+ int i, mx;
+ if( pIn==0 ) return 0;
+ mx = pIn[1];
+ i = 2;
+ do{
+ const char *z = (const char*)&pIn[i+2];
+ if( strncmp(z,zName,nName)==0 && z[nName]==0 ) return pIn[i];
+ i += pIn[i+1];
+ }while( i<mx );
+ return 0;
+}
diff --git a/src/vdbe.c b/src/vdbe.c
index 1093622..6d24326 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -1190,7 +1190,7 @@
Mem *pVar; /* Value being transferred */
assert( pOp->p1>0 && pOp->p1<=p->nVar );
- assert( pOp->p4.z==0 || pOp->p4.z==p->azVar[pOp->p1-1] );
+ assert( pOp->p4.z==0 || pOp->p4.z==sqlite3VListNumToName(p->pVList,pOp->p1) );
pVar = &p->aVar[pOp->p1 - 1];
if( sqlite3VdbeMemTooBig(pVar) ){
goto too_big;
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index dbdde00..3e6bb06 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -346,7 +346,6 @@
Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
Parse *pParse; /* Parsing context used to create this Vdbe */
ynVar nVar; /* Number of entries in aVar[] */
- ynVar nzVar; /* Number of entries in azVar[] */
u32 magic; /* Magic number for sanity checking */
int nMem; /* Number of memory locations currently allocated */
int nCursor; /* Number of slots in apCsr[] */
@@ -371,7 +370,7 @@
char *zErrMsg; /* Error message written here */
VdbeCursor **apCsr; /* One element of this array for each open cursor */
Mem *aVar; /* Values for the OP_Variable opcode. */
- char **azVar; /* Name of variables */
+ VList *pVList; /* Name of variables */
#ifndef SQLITE_OMIT_TRACE
i64 startTime; /* Time when query started - used for profiling */
#endif
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 213ba83..32794de 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1470,10 +1470,8 @@
*/
const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
Vdbe *p = (Vdbe*)pStmt;
- if( p==0 || i<1 || i>p->nzVar ){
- return 0;
- }
- return p->azVar[i-1];
+ if( p==0 ) return 0;
+ return sqlite3VListNumToName(p->pVList, i);
}
/*
@@ -1482,19 +1480,8 @@
** return 0.
*/
int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
- int i;
- if( p==0 ){
- return 0;
- }
- if( zName ){
- for(i=0; i<p->nzVar; i++){
- const char *z = p->azVar[i];
- if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
- return i+1;
- }
- }
- }
- return 0;
+ if( p==0 || zName==0 ) return 0;
+ return sqlite3VListNameToNum(p->pVList, zName, nName);
}
int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index cfc07ba..53aedf4 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1975,10 +1975,8 @@
x.nFree = x.nNeeded;
}while( !db->mallocFailed );
- p->nzVar = pParse->nzVar;
- p->azVar = pParse->azVar;
- pParse->nzVar = 0;
- pParse->azVar = 0;
+ p->pVList = pParse->pVList;
+ pParse->pVList = 0;
p->explain = pParse->explain;
if( db->mallocFailed ){
p->nVar = 0;
@@ -2982,8 +2980,7 @@
}
if( p->magic!=VDBE_MAGIC_INIT ){
releaseMemArray(p->aVar, p->nVar);
- for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
- sqlite3DbFree(db, p->azVar);
+ sqlite3DbFree(db, p->pVList);
sqlite3DbFree(db, p->pFree);
}
vdbeFreeOpArray(db, p->aOp, p->nOp);